Why Color Inversion?

Ching-Chang J. Tsai
Saudi Aramco
[email protected]

Many inversion techniques such as model-based and stochastic inversions are commonly used to derive acoustic impedance. Impedance values could be related to lithology, porosity or fluid content. While these methods are popular, another approach called color inversion (CI) is also available and gradually gaining acceptance by many geophysicists. Color inversion has several advantages over conventional approaches. The main advantage is that it is conceptually simple and exceptionally easy to run. Unlike conventional inversions that are difficult to understand and involve complex procedures, CI derives and applies a simple convolution filter to seismic data to obtain band-limited impedance. Due to its filtering process, CI is so fast that job turnaround time is in hours. Using conventional inversion, and not counting preparation time, the same job could easily take five or ten times that of CI. When dealing with large 3-D datasets, CI thus affords more time for interpretation and assessment of exploration targets. Another advantage of CI is that it is data-driven. It does not need an initial impedance model in the inversion process. Any observed anomaly or change in impedance is driven by the input seismic data. This is in contrast to the conventional inversion in which the initial model is required and has a significant contribution to the final inverted impedance. This is important in dealing with exploration prospects where few wells are available. In this presentation, examples will be provided from Saudi Arabia to demonstrate the advantages and applications of color inversion.

AAPG Search and Discovery Article #90077©2008 GEO 2008 Middle East Conference and Exhibition, Manama, Bahrain